ceph/src/boost/libs/mpl/doc/src/refmanual/minus.rst

   1 .. Metafunctions/Arithmetic Operations//minus |20
   2
   3 minus
   4 =====
   5
   6 Synopsis
   7 --------
   8
   9 .. parsed-literal::
  10
  11     template<
  12           typename T1
  13         , typename T2
  14         , typename T3 = |unspecified|
  15         |...|
  16         , typename T\ *n* = |unspecified|
  17         >
  18     struct minus
  19     {
  20         typedef |unspecified| type;
  21     };
  22
  23
  24
  25 Description
  26 -----------
  27
  28 Returns the difference of its arguments.
  29
  30
  31 Header
  32 ------
  33
  34 .. parsed-literal::
  35
  36     #include <boost/mpl/minus.hpp>
  37     #include <boost/mpl/arithmetic.hpp>
  38
  39
  40 Model of
  41 --------
  42
  43 |Numeric Metafunction|
  44
  45
  46 Parameters
  47 ----------
  48
  49 +---------------+---------------------------+-----------------------------------------------+
  50 | Parameter     | Requirement               | Description                                   |
  51 +===============+===========================+===============================================+
  52 | |T1...Tn|     | |Integral Constant|       | Operation's arguments.                        |
  53 +---------------+---------------------------+-----------------------------------------------+
  54
  55 |Note:| |numeric metafunction note| |-- end note|
  56
  57
  58 Expression semantics
  59 --------------------
  60
  61 For any |Integral Constant|\ s |c1...cn|:
  62
  63
  64 .. parsed-literal::
  65
  66     typedef minus<c1,\ |...|\ c\ *n*\>::type r;
  67
  68 :Return type:
  69     |Integral Constant|.
  70
  71 :Semantics:
  72     Equivalent to
  73
  74     .. parsed-literal::
  75
  76         typedef integral_c<
  77               typeof(c1::value - c2::value)
  78             , ( c1::value - c2::value )
  79             > c;
  80
  81         typedef minus<c,c3,\ |...|\c\ *n*\>::type r;
  82
  83 .. ..........................................................................
  84
  85 .. parsed-literal::
  86
  87     typedef minus<c1,\ |...|\ c\ *n*\> r;
  88
  89 :Return type:
  90     |Integral Constant|.
  91
  92 :Semantics:
  93     Equivalent to
  94
  95     .. parsed-literal::
  96
  97         struct r : minus<c1,\ |...|\ c\ *n*\>::type {};
  98
  99
 100 Complexity
 101 ----------
 102
 103 Amortized constant time.
 104
 105
 106 Example
 107 -------
 108
 109 .. parsed-literal::
 110
 111     typedef minus< int_<-10>, int_<3>, long_<1> >::type r;
 112     BOOST_MPL_ASSERT_RELATION( r::value, ==, -14 );
 113     BOOST_MPL_ASSERT(( is_same< r::value_type, long > ));
 114
 115
 116 See also
 117 --------
 118
 119 |Arithmetic Operations|, |Numeric Metafunction|, |numeric_cast|, |plus|, |negate|, |times|
 120
 121
 122 .. copyright:: Copyright ©  2001-2009 Aleksey Gurtovoy and David Abrahams
 123    Distributed under the Boost Software License, Version 1.0. (See accompanying
 124    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)